In the case of uniform circular motion,which of the following physical quantities does not remain constant?

$A$ particle is moving in $U.C.M.$ with speed $V$ and radius $R$. The angular acceleration of the particle is

$A$ particle is performing uniform circular motion along the circumference of a circle of diameter $1 \ m$ with a frequency of $4 \ Hz$. The acceleration of the particle in $m/s^2$ is (in $\pi^2$)

If ${a_r}$ and ${a_t}$ represent radial and tangential accelerations,the motion of a particle will be uniformly circular if

As shown in the figure,a particle is moving with a constant speed $v = \pi \, m/s$ in a circular path. Considering its motion from point $A$ to point $B$,where the angle subtended at the center is $120^{\circ}$,the magnitude of the average velocity is:

$A$ particle is moving in a circle of radius $r$ with center at $O$,with a constant speed $v$. The magnitude of the change in velocity when moving from point $A$ to point $B$ is